Electrical socket



G. B. Pol-LOCK ELECTRICAL SOCKET Aug. 2, 1949.

Filed Feb. 4, 1946 2 Sheets-Sheet 1 INVENTOR. Garden .ioclc dTTOHNEY 1949- v G. B. POLLOCK 2,477,895

ELECTRICAL SOCKET Filed Feb. 4, 1946 2 Sheets-Sheet 2 INVENTOR. Gordon 5. Pallock ATTORNEY Patented Aug. 2, 1949 UNITED, TA ES PATENT OFFICE ELECTRICAL SOCKET Gordon Pollock, South Laguna, Calif.

Application February 4, 1946, Serial No. 645,447

an abrading' type of electricalsocket or the like, adapted to mechanically'and electrically engage the electrical contact portions of the bulb or other element to be received within the socket, andv to retain such bulb or the like in such socket.

A further object of the invention is to provide an abrading type of electrical socket for recep tion of an electric bulb orthe like, wherein at least one of the abrading elements adapted to make electrical contact is adapted to function as a resiliently biased retaining means to maintain such bulb or the like within the socket in electrically operative position.

A further object of the invention is to provide an abrading type of electrical socket for reception of an electric bulb or the like and having one electrical contact of the spring-biased type adapted to resist the insertion of a bulb, together;

with another electrical contact member also of a spring-biased type adapted to'mechanically and electrically engage the bulb during the insertion thereof and retain the same within such socket against the biasing actionof the first-named elec trical contact member, such last-named electrical;

contact memberbeing releasable to permit ejection of the bulb from such socket under the influence of said; first-named electrical contact member. 1

In many electrical'uses, 'where itis desired to make an electrical connection of the type where a plug-like element is inserted within a tubular or recessed element as the electrical contact is made, it is essential or at least desirable to cause the electrical engagement "of the contact membersto present'a desired minimum electrical re- In particular, in so-called flash sistance. bul photography, the character of the electrical contact obtained upon insertion of a bulb great-f ly influences the instant ofignition of the bulbin the production of the required flashl' Ordinarily, it is the practice of skilled photographers to employ a ratherstrong source-of energy for 1 Claim. :(Cl. 173-328) time one set of batteries appears to be useful,

the ignition of the bulb, so as to overcome slight differences in the electrical resistance of the socket, to thereby reduce the percentage error in the ignition time of the bulb. It will be appreciated that when shutter speeds on the order of /200 second are employed in a camera, an unwanted delay of /50 second in the ignition of the flash bulb might well result in loss of the photo-'- graphic exposure, without knowledge thereof on the part of the photographer.

Asa further expedient to reduce the possibility of a delayed ignition of the bulb, many photographers make the practice of abrading the bulb tip (usually of soft-solder-like metal) upon some material such as sand-paper, to remove any accumulated dirt or film of oxidized metal from the contact. It is not appreciated, however, that the base-portion of the bulb (at which one side of the electrical circuit is established may also be of varied electrical resistance characteristics, and little or no efiort is made to compensate or correct for this condition.

I have determined that when a positive electricausing the contact elements within the bulbsocket to exert a positive abrading action at the position of the electrical contacts, whereby a consistent minimum electrical resistance is obtained, energy sources such as electrical batteries may be made of considerably less power (with a consequent saving in weight) and very consist-. ent results obtained over a relatively long period. For example, while itis common practice among commercial or news photographers to use three fresh medium size batteries in series (4.5 volts) to flash a General Electric #5 flashbulb, I have found that it is entirely practicable to flash this type of'bulb with two pen-light batteries in series, and to continue to flash such bulbs over a materially longer period than has heretofore been considered practicable without de-synchronization of the shutter and flash; the length of when a socket of the type considered by this application is employed, appears more to be limited by the available shelf-life of the batteries, than by the number of flashes which have been effected.

' The socket construction of my invention is adapted particularly for reception of and contact with an electric lamp or element of the bayonet base type, in which one of the contact areas of the element is provided by the smooth side wall of the base, which is generally cylindrical in shape and extends parallel to the direction of.

3 relative movement thereof in inserting the element in the socket, the other contact area of the element being provided at the inwardly disposed end of the base, generally centrally thereof.

According to the present invention, I provide a socket construction in which the central contact is of an abrading type, such as a pin member or conical point which will penetrate the soft-metal tip on the bulb, and arrange a second abrading contact element within the socket-in position to engage and "abrad'e the side-wall portion of the bulb-base as it is inserted within the socket, thus providing positive abrading contacts at the two electrical positions required for the completion-of the electrical circuit to the fiashbulb. According to the preferred construction, I provide the second contact element in the relation of a retaining means for the bulb, whereby the bulb is firmly engaged by such contact element and caused to persist within the socket.

In its broader aspects, the invention is ooncemea 'with a socket construction adapted -to receive an electrical element having at least one cdritact "area at which an electrical connection is't'ob'e made, wherein an abrading and retaining type of contact member is provided to engage such contact area and make both a mechanical and electrical engagement. Further, the construction may include spring means adaptedto b'e'stres'sed upon placement of such element within the socket, to produce a biasing action tending to 'e'jec t'the'element 'from'the socket, which action is opposed by the abrading-retaining contact member. 'The construction may comprise, for simple flash-bulb use, merely two abrading contact members adapted to respectively engage the spaced contact areas on the bulb-base, to establish a minimuin electrical resistance upon insertion of the bulb within the socket.

Other objects and features of this invention willbe'brought out in the ensuing descriptionof certain illustrative 'forms of construction, or will bev apparent from such description with reference to'the accompanying drawingajin which:

Fig. '1 is apartly fragmentary vertical section of a so-called flash-gun, provided with asocket construction according to this'invention;

Fig. 2 is a rear elevation dffthefform shown'in Fig. -1, as takenon'line 2- 2 therein; I H

Fig. "3 is a verticalsection of a modified-form of socket construction, showingafias'hbulb retained therein; V

'4 is a. plan view of the form shown in Fig. 3, as taken 'on'line 4- 4 therein;

Figs. '5 through "'7 are transverse sections through -a camera 3 body :provided with a socket construction according to this invention, taken inthree different.planes Figs 5-and 7 being taken on lines 5-? and "1-1:respectively in-Eig. 6, and Fig. fi being taken on line-6 6 inFig. 7,and

Fig. 8 is a vertical fragmentary-section of -a camera case provided with a -form of abrading socket construction according to =this invention, in which conventional retaining means-are ,-provided to retain a bulb orlikeelement within the socket.

"Referring to- Figs. 1--and-2=of-the drawings, a flash-gun reflector is indicated at l, having a central mounting opening zdnto whiche socket 3-extends,-the reflector -i being carried against the rearward surface of-aforward= flange '4- on'the socket-3. -The bulb-retaining andcontactmeans 5 may comprise-anapertured body iportion -6 of metal-disposed about-the-sockete, an attachment portion J-riveted or otherwisesecured to -a -batthe 'body portion 6.

4 tery case or handle portion 8, and an elongated portion 9 punched out to define an electricallyconductive and resilient bulb-retaining and contact finger ID. The finger I0 is adapted to extend within a longitudinal slot II in the socket with the free end thereof adapted to engage the base .of a bulb inserted within the socket. Means are provided for releasing the finger [0 from engagement with the bulb base, such as a release lever f2 provided at one end with pivot arms l3 to retain the lever l2 with respect to the portion 9, suitable retaining recesses l4 being provided in the portion 9 to receive the arms l3. The

--sooket 3, refiector l and bulb-retaining and contact means 5 may be interconnected in operating position through "the agency of a snap ring l5 disposedina-suitable annular recess in the socket 3 and bearing against the rearward surface of The lever I2 is provided with an opening I2a through which the finger I0 projects, the edge portion -of the opening l-2a serving as a cam to-li ft the finger out of the -fullline .position to the dot-dash position ffla =upon depression of the lever to the position +212.

'I he socket 3 -is :provided with a central -bore H3, at "the rearward end of whiohI provide a central contact member L1 zprovided with aforwar'cily directed abrading contact point 48. :An ejector-spring I9 is cprovided to bias the contact 1 forwardly, as against a shoulder 2| on the contact -I l, and a rearward-shoulder -21 a is provided to prevent the-spring 48 from driving-the contact I 'l out -of the'bore 16. Anelectrical'connector 22 is provided, :leading to one side of the source of energy tor the-flash-bulb. 'The -fiashis attached to thesocketibypassingthe bulb-base -24 into the-bore 46, the conventional bayonet .prongs 25 (which are-not utilized -in-retaining the bulb within; the=socket 3-) beingcaused to enter Zlongi-tudinal slots -26 -in the-socket. As the bulb-base 24 isipushed-intothe-bore 16, the centrally disposed contact 21 on the bulb base will befp rced into engagement with --the central cpntact l'L and as it-is usual that the contact 21is}armed-ctarelatively-soft, solder like-meta1, the abrading point 18 of the contact -I-1 will be forced --into =the contac't t! where fresh metal will be engaged-twining a very satisfactorycons tact. The insertion of =the bulb base also causes the-smooth sidewa1l portion of thebase 24 which extends parallel to the direction of movement .of the :bulb, to be engagedby thaabrading-point 28 on-thedreeend of the fingerMLwhich will scrape along suc'h side-wall portion and abrade thesurface thereof. This serves toremoveany accumulated oil, .grease, dirt or :ether relativly high electrical resistance wntaminant, andYthis-abrad ing lpoint 2:8 may actually be caused to scrape down into the metal of the base lZ'4, -providing-a very low resistance contact. 'I'Ehe return circuit for'the'battery or other source of energy may be conducted through the finger L the portions 6, Land-9 0i the bulb-retaining means to the .battery case 8, -where it may eonnect to the-opposite side of-the battery from that to which the .conductor :22 is connected.

PWhen -the bulb 23 has beenmushe d inas-rar as it is desimm-thabiasbuilt -up inthe spring [May the rearward movement of the contact 4-1 will serve to crowd=the-bulbbasel4 outwardly against the-ho]ding actiomofrthespring.fingert0,- causing the -same "to -more firmly abrade "the -s-ide--wall portion. When it --desired to release -a spent bulbdrom the socket, 'it is merely necessary -to depress the release lever L2 to the dot-dash =position l2b, pulling the free end Illa of the finger ||l away from the side-wall of the bulb-base, whereupon the spring l9 will eject the bulb from the socket bore l6. Y

Referring to Figs. 3 and 4 of the drawings, I have illustrated a modification of the structure shown in Figs. -1 and 2, wherein the retaining finger which is adapted to engage the side wall portion of the bulb base is formed as a separate element, pivotally mounted with respect to the socket member. This form of the device may comprise a support 3|, to which a socket 32 and a reflector 33 are attached throughthe agency of a snap ring 34. The bulb-retaining and abrading means may comprise a base member 35 carrying a retaining finger 36 having an abrading contact point portion 31 operating through a slot 38 in the side-wall of the socket 32 and adapted for pivotal movement through a minor angle with respect to the base 35 as through a pivot pin mounting 39 which may be defined by upstanding ears 46 and depending ears 4| on the base 35 and the finger 36, respectively. A spring member 42 may be coiled about the pivot ,pin 39, with portions extending into biasing engagement with the members 35 and 36, to exert a rotative effort upon the finger 36 in a counterclockwise direction as viewed in Fig. 3, and cause the contact point 31 to resiliently engage the side wall of the base 43 of a bulb 44. This spring 42 is shown in dotted lines in Fig. 4; omitted in Fig. 3. As the bulb is inserted within the socket 32, the point 31 will be engaged, and the finger 36 rotated clock-wise as to the position shown in full lines in Fig. 3, and the desired release of the abrading point 31 may be obtained by depressing the extension 45 of the finger 36 outwardly of the pivot 39, moving the finger 36 as to the dotdash position shown in Fig. 3.

The socket 32 is provided with a spring contact construction comparable to that shown at |1-2| in Fig. 1, as at 46. The socket 32 may be of metal, if desired, in which case the rear wall thereof is preferably formed of insulating material, and may comprise a washer 41 inserted within a recess at the rearward end of the socket and maintained therein by spinning the end portions of the socket over the washer as at 4B. The retaining finger 36, the base member 35 and support 3| may be formed of electrically conductive material such as metal, whereby the desired supply of electric energy to the bulb 44 may be established through lead 49 and the contact 46 for one side and through the support 3| base member 35 and finger 36 to the other side. i

In Figs. 5-7 I have shown a form of this invention which is incorporated in the body or casing portion of a camera, for example, and referring thereto a camera body portion is indicated at 5| provided with a tubular portion 52 defining a socket adapted to receive the base portion 53 of a bulb 54. The tubular portion 52 is recessed at opposite sides, as at 55, to receive the customary bayonet prongs with which the bulb 54 is usually provided, and at a position removed from the location of the grooves 55 I provide a slot 56 within which the bulb retaining means may function. In this form of device the bulb retaining means may comprise a lever member 51 having a contact portion 51a disposed within the slot 55 and terminating in an abrading point 58 which is adapted to engage the side wall of the bulb base 53 in a manner corresponding to engagement provided at 28 and 31 in the first described forms of the device. The lever member 51 is mounted to establish a swinging movement "of the portion 51a within the slot 56 as between the'full line and dot-dash positions illustrated in Fig. 5, andto this end I may provide the lever member 51 with a straight central portion 51b which is pivotally attached to the camera casing 5| within a suitable elongated channel or groove 59, and retained therein by staking or the like as at 60, together with an actuating portion 510 depending within the casing 5| and adapted to be engaged by an operating member 62. The operating member may comprise a shoulder member 63 mounted on a push rod 64 carrying a push button 65-extending through the side wall of the casing. in position for manual engagement, said rod member and the shoulder 63 being biased outwardly through the agency of a spring member 66. The shoulder member 63 is thus biased to the left, in Fig. 5, causing a clockwise rotation of the lever 51, carrying the portion 51a to the full line position illustrated. The desired retraction or movement of the portion 510. out of contact with the bulb base may be efiected through the agency of a second shoulder member 61 preferably spaced from the shoulder 63 sufliciently to receive the depending lever portion 510. The portion of the shoulder 61 facing the lever portion 51c is pref erably tapered as at 61a to facilitate the smooth rotative operation of the lever 51 when the button 65 is pressed inwardly.

The operation of this form of device will be apparent from the drawings and the above de: scription, it being comprehended that a spring contact assembly 68 comparable to structures |1. 2| and 46, above, will be provided to secure-the desired abrading contact of a central terminal of the bulb and the desired ejection of the bulb from the socket upon release of the lever 51, the desire electrical supply being provided through lead 69 and the casing 5|. 1

In the forms of device shown in Figures 1 through 7, the free end portion of the bulb retaining means which functions to secure the desired abrading contact of the bulb base side wall, is inclined forwardly in the direction of insertion of the bulb-base within the socket so that a toggle action is obtained upon the bulb retaining means under the biasing influence of the spring contact which engages the central terminal of the bulb, this action causing the biasing effort exerted by the central spring contact to result in a more firm abrading engagement with the bulb side wall; the greater the biasing efiort exerted by the spring upon the central contact, tending to eject the bulb from the socket, the

greater the resulting retaining action of the bulb retaining means, and the more intimate the abrading electrical engagement of the retaining means with the electrical contact defined by'such side wall of the bulb-base.

The lateral thrust against the bulb-base side wall effected by the abrading retaining fingers I0, 36 and 51a will push the bulb-base toward the opposing side wall of the socket bore, and where such socket is of an electrically conductive nature, as in Figs. 3-7, this will contribute to the desired low electrical resistance.

Fig. 8 I have illustrated an abrading contact structure adapted to provide abrading engagement with the central contact and side wall portions of a bulb-base, where reliance is placed on other means for retaining the bulb in place with the socket, thus attaining the electrical advantages of this invention. Referring to this figure, a socket construction is illustrated at 1|,

provided with :a central fabrading contact H2 provided :with :a biasin spring 33 :and aadapted lto engage the central terminal-fill ot a bulb 'ba'se such bulb Ebase being retained within the socket Ell'l through-the agencysof the conventional bayonet prongs Iii-in :cooperating with a lriayonetslot construction :1 of eonventionalform in the-sockct itself. The electrical contact to aha-side wallo'f thebase 1521s provided through a resilient-spring contact-member 18 secured to afixediportionof the socket assembly such as a support 19 and carrying an :abrading .point 80 :at :its free end pm'tinn, which .point 139 lmay be extended through a suitable :opening '8'! in the side wall of the socket FM. Upon :insertionfoflthc bulb within :a socket ill the base I5Lis mechanically and electrically engaged .by the 'labrading .point Bawhich scratches .into the base metal through any accumulated interferingfilm at Tthaside wall portion of the base, while the point 182 oftthe central spring :contact assembly .will penetrate and electrically engage with the terminal 14.

Numerous imodifications in the structure A of 1 this invention WilllOGClll' to -th'ose skilled in the artgth'e delineated :forms of therinvention being illustrative only, andlflchoose therefore not'to belimited to :thesspecific -details herein setiorth but rather to the scope of :Ithe :subjnineol claim.

It will he understood :that the abrading "contact portions 28, 31, SBan'd B'll in "the above described embodiments of my invention are each provided lwithlazsharp-edge 'or point (as illustrated most nlear lyiinTFigs. J sandfi) positioned forengagementwith the contactiareaat the smooth side wall :portion of :the bulb base so as to not only scratch through-anyaccumulated interfering film on such contact area butinto the metal itself, thus Lcuttingiinto or fscarifying the metallic :suriace, :whereby they attain mechanical engagement with the bulb base as well as providing low resistance electrical "contact.

Furthermore, it .will be appreciated'that the abrading nontact means vemployed atith'e central contaotzoneflfor :example, or the abrading contact :means shown at Illa, 131, 58 "or 'ilil are not necessarily mounted directly upon the guide meansia'dapted to receivexthe bulb-base orother oonnection'element; however, for the purpose :of simplification f wording, the ibroadtterminology of "the subjoined :claim refers to such nontact means :as 'being :mounted ;upon thev'rguide :means, and 'it is my intention that 'this expression be interpreted as includingstituctures in 'which the contact means may he supported in some =genera'llyrfixed relation'zto'the gui'deuneans, as 'being mounted upon an ancillary structural :element whichiis :relativelyrfixed with :respectTto theguide means. "As in Fig.1}, :for example, the contact member 80 is*mounteduponfthe support 18, which may the integral with 'orimerely attached to the socket II.

I claim:

An electrical socket construction adapted for the :reception and retention of an electrical elementprovided with two spaced contact areas at which cel'ectrical conn'ections are to be established upon relative movement of said socket and said elementwith respect to one another, one 0f said contact areas abeing disposed at the inner end- 0f said elementzand the other of said contact areas having a smooth :surface extending parallel to theidirection "of 'such relative movement, which comprises: means defining a guide member 'for reception-:dfzsaidelement; electric contact means at thelinnenendofsaid guide member in position to engage :said one contact area of said element uponreception-of said element within said guide member-and provided with an abrading member adapted :toleifect an abrasion of said one contact areaduringisuch engagement, said contact means being :provided with spring means biasing the same outwardly of the socket toward one position and being movable inwardlyaway from said one position against -:such bias by engagement with said cone contact area=upon insertion of said-element within said guidemember to thereby cause suchxliias to :be imposed upon said element in such-opposite direction; and an electrically conductive toggle member mounted in fixed'relation with lespect to said :guide member at one side .-REFERENCES CITED 'The 'followingreferemces are of record in the file of 'this patent:

UNITED STATES :PATEN IS Number Name 'Date '1j221j524 'Fran'kel Apr. 3, 1917 153L049 Thompson Mar. 24,1925 1,675,163 "Colburn June 26, 1928 794,976 Mueller Mar. 3, 1931 1,910,022 l' egg May 23,1933 21206;?99 Barton 'July '2, 1940 22935660 Nicholas Aug. 18, 1942 23081016 Nlihalyi Jan. '12, I943 

